Aircraft manufacturers often develop families of aircraft in which subsequent versions are able to carry more passengers and/or cargo than the earlier versions. Increasing the passenger and/or cargo capacity is typically accomplished by stretching the fuselage and/or increasing the wing area. One prior art approach for increasing wing area is illustrated in FIGS. 1A-2B.
FIG. 1A is a top view of a baseline wing assembly 100 configured in accordance with the prior art, and FIG. 1B is a rear view looking forward at the baseline wing assembly 100. Referring to FIGS. 1A and 1B together, the baseline wing assembly 100 includes a baseline wing 102 and a winglet 104. The winglet 104 is fixedly attached to a tip portion 106 of the baseline wing 102. Although the chord length of the tip portion 106 is minimized for aerodynamic reasons, it is still long enough to allow human access for fixedly attaching the winglet 104 to the baseline wing 102.
FIG. 2A is a top view of a derivative wing assembly 200 configured in accordance with the prior art, and FIG. 2B is a rear view looking forward at the derivative wing assembly 200. Referring to FIGS. 2A and 2B together, the derivative wing assembly 200 includes a constant-chord tip extension 208 for increasing the wing area of the baseline wing 102. The constant-chord tip extension 208 includes an outboard end portion 206 spaced apart from an inboard end portion 205. The inboard end portion 205 is fixedly attached to the tip portion 106 of the baseline wing 102, and a winglet 204 is fixedly attached to the outboard end portion 206. The winglet 204 can be at least generally similar in structure and function to the winglet 104 illustrated in FIGS. 1A and 1B.
Although it may be advantageous from an aerodynamic standpoint to taper the constant-chord tip extension 208, this is not possible from an assembly standpoint because the resulting tip chord would be too small to accommodate human access for attachment of the winglet 204. For this reason, the chord length of the outboard end portion 206 is the same as the chord length of the inboard end portion 205 (hence the term “constant-chord”). One downside of this approach, however, is that the resulting planform of the derivative wing assembly 200 is not optimized for aerodynamic performance.